Prior art machines for applying closures to containers are well known in the art, and typical examples are U.S. Pat. Nos. 2,819,577, 3,054,240, and 4,089,153, the subject matter of which is incorporated herein by reference thereto. Various types of closures can be applied by these machines depending upon their particular configuration, the most common being roll-on caps, screw-on caps, and stake-on caps. In all of these designs the closure is applied in a turret, the closure being carried by a chuck which applies the closure as the containers are conveyed about the centerline of the turret, the chuck rotating about its centerline as the closure is applied.
The turret includes a rotatable portion and a fixed portion. A plurality of spaced apart chuck assemblies are carried by the rotatable portion of the turret, each chuck assembly being spaced away from the centerline of the rotatable portion of the turret, and each chuck assembly being rotable about its own centerline which is parallel to the centerline of the turret. Disposed below the chuck assemblies is a rotatable conveyor in the form of a star wheel or the like, containers being carried by this conveyor in axial alignment with the chuck assemblies. Disposed adjacent the turret assembly is a transfer table on which closures are placed for pick up by each chuck assembly. In these prior art machines the closures are generally of a circular cross-section and the orientation of the closure with respect to the container is not material. In one typical example, the closure will be picked up from the transfer table by a chuck assembly, for example the type as shown in U.S. Pat. No. 3,961,463, the subject matter of which is incorporated herein by reference thereto. After the chuck assembly and closure clear the transfer table, the chuck assembly will be lowered by a cam mechanism the chuck assembly also being rotated to screw on the closure onto the container. When the proper torque is achieved, the chuck assembly will spring open even though continued rotational movement is being applied to the chuck assembly. The rotatable portion of the turret continues to convey the container with the assembled closure until it is discharged, and the chuck assembly will be shifted back to a raised position where it can again pick up another closure to be applied to another container. The operation of these machines is well-known in the art and are sold to the trade as "CaPeM" capping machines by the Consolidated Packaging Machinery Company of Alden New York.
In the prior art machines with screw-on chuck assemblies, it has not been necessary to precisely position the chuck assembly with respect to the closure beforehand as the exterior surface of screw-on closures is generally circular. Therefore, the chuck assembly could be in any position of orientation with respect to the closure when the closure is initially engaged. This would also be the case with roll-on caps and with stake-on caps which are of a circular cross-section.
In prior art machinery where stake-on caps are applied to containers where the cap has a non-circular cross-section, the cap or closure has generally been presented to the assembly area in a specific orientation with respect to rotation, and it has also been the case that the container has also been provided in a specific orientation so that it is only necessary to pick up the cap, position it over the container, and bring the parts together to stake the closure onto the container. For example, the closures and containers may all be delivered to the assembly area of the container to that their fronts all face out.
A new container/closure assembly has recently been developed which will permit assembly of the closure onto the container by staking only when the closure is in one rotational position of orientation with respect to the container. However, this same container/closure design will permit rotation of the closure relative to the container in one direction of rotation until a stop on the closure engages a stop on the container to establish a correct position of orientation, at which time the closure can then be moved towards the container a distance sufficient to stake the closure onto the container.